I sometimes get calls/emails about where I find the images that I use when designing. There are many sites available, but the two that I rely on the most are DesignPics and Istockphoto – because of their large selection and their reasonable pricing.
With DesignPics I have an account (I pay a set fee every year and get to download a certain number of pictures). Istockphoto works a little differently, you purchase credits (I normally purchase 50 credits at a time) and the you can download images – they all have a credit value (5, 10, 15, etc).
When buying or using a specific image from a stock photography site it is important to make sure that the image is royalty free (both DesignPics and Istockphoto carry royalty free images only). Royalty free is a term stock photography agencies use to denote that an image is licensed for multiple use (ie – more than one company can use the image at any give time). Images that are not royalty free tend to be very expensive.
There are many image sites that exist where you can download images for free. Make sure you read the requirements for using the images for printing purposes or in a public forum, as you may be limited. Often the site requires that the image be identified and credit given to the photographer.
If you have resources that you have found and enjoy using – let us know!